Shout out to G and J for outstanding work. Thank you!! Great place to be. These guys and gal, are super friendly and always willing to help. Thanks

Great Place! People there were very informative and friendly on a few issues I had. They seemed to be more customer oriented than many other custom shops that Ive been to in the past, breath of fresh air. Thank you guys, next time Im in Billings, MT Ill definitely be swinging in.

We broke down in Billings and they were very accommodating. They got us in as quickly as possible and they worked hard to get us back on the road. They were very friendly and informative. We felt that they were very fair and did a great job.

Great shop!

Gave an accurate estimate, scheduled and performed the work in a timely fashion with quality parts and labor. Staff was courteous, friendly and knowledgable. Will use their services again.

Great place and great people!

Great place just need to expand I feel to work on gas motors just not diesel

Great service and helpful friendly staff. Did not try to hide anything and were upfront about the repairs. Sam was great and provided excellent customer service.

Great people and great parts very knowledgeable staff

Great experience. Called for an exhaust and told me it was in stock. Showed up a day later, they remembered who I was and grabbed the exhaust. They made sure it was the correct one even before taking my money. As we waited for them to load the box for us, they gave my son a ton of cool race stickers for his go-kart. Will definitely be back for my cold air intake.

The service is amazing I never have any problems when I go to G&J Diesel. I would recommend it to a lot of people. I’ve been going here for over 10 years.Thanks a bunch,Mark Stradtman

I took my truck to G & J after having a bad experience elsewhere. In the few days that they had the truck, they not only fixed the issues, but they were informative and kept me in the loop all the time. Even on the smallest of repairs, they did not perform any work until they received my approval. G & J is a great company to do business with and I highly recommend them. Furthermore, as a first-time diesel owner, I was unsure of some of the operations of the truck. Brad, the owner, took time on a Saturday, when they were closed, to drive the truck with me and answer all of my questions. My experience here was excellent and I will recommend them from now on.

Great place good people. Reasonable priced just did an oil pump for me in one day thank you guys

Only been a week since repairs were done but 2007 ram 5.9 running strong as ever. Price was a little higher than i wanted to pay, but between their reputation and the fact that diesel is what they do, not a sideline, itll be worth it if theres no hiccups when hunting. Good advice: feel the pain once and have it done right the first time.

Im a delivery driver for a intrastate courier, and I pickup and deliver many packages for G&J. The staff is always super friendly and very professional how they handle the calls and personal exchange in person. I absolutely love seeing them in the mornings when they have packages needing to go out to their customers. The customers always have good things to say about G&J.

I should have reviewed sooner. G&J was recommended by a co-worker who is a fantastic diesel and heavy equipment mechanic. Maverick (my 02 5.9 HO) runs better every visit. G&J has adjusted the timing, replaced wheel seals, replaced brakes, installed shocks, and installed a beautifully crafted MBRP Quiet tone exhaust.Sam is friendly and thourough. G&J will be my go to on my way to 1 million miles (220k now)

What I like about G & J, is that they are up front and honest. If they feel repairs need to be done after the diag is completed in order to save a vehicle from no longer running, they give an honest to god estimate. It might not be what you want to hear, but it at least gives you an idea of where to begin. Their diagnostic/ mechanic team is fantastic and all of the office employees hands down know their stuff. I would recommend G & J to anyone with a diesel!

Very friendly and professional service. The crew was sensitive to my needs and got my vehicle repaired in a very timely manner. Would definitely recommend G&J to friends.

Helpful and answered every question I had

Fast, knowledgeable, professional, and honest. They even called days later to make sure we were satisfied.

G&J Diesel were very professional and knowledgeable from the first phone call. I had read an article about 6.7 powerstroke feul pump failures and that there was a fix for it, I called G&J Diesel for their advice on the article I read. They confirmed that a failure of the pump would cause thousands of dollars of damage to my engine and that they have the kit that will stop the failed components from entering the fuel rails and injectors. Got an appointment for the next week and it was done by noon. My engine was clean no leaks and I was very impressed with the everyone there. I will definitely be back, great company

G&J Diesel repair treated me great and went up and above to get my rig rolling again..Highly recommend. Two thumbs up!

The wrong differential was ordered for my truck, which delayed the completion of work. However, every effort was made to get my truck back to me when I really needed it. There has been great follow-up since I got the truck back.

Called in cause I needed some front end work done and I needed it done by today. They are hard at work so I can get back home. They call with check ups and even helped me out when another towing company was taking my truck. These individuals are amazing and I will do further business with them in the future.

Had my block machined there. Good service and reasonable rates.

Brad and the guys and gals at G&J have always performed above whats expected and usually found at the other shops who claim to work on diesel trucks. They have performed my repairs and maintenance for several trucks now and have done a great job. I had to take one 7.3 Ford to another shop and they even fixed all the mistakes from that shops certified techs work now.Lesson learned, wait your turn at G&J and get it repaired right.Thanks guysJim B

Very knowledgeable and excellent service! Expensive!!! But, honestly I felt I got exactly what I paid for. Absolute quality. These guys bent over backwards for me. I ran into problems thousands of miles from home, on vacation. They took a fairly stressful situation and cured it in a timely manner. Thank you to all of the staff.

Awesome friendly staff.these people know what they are speaking about.good location.nice atmosphere. Knowledgeable staff..

Great communication and attention to detail. Thanks G&J!

Amazing place to do bussiness!!!! Always professional help. Been 12 years goin in and will be many many more.

Had a wonderful experience with these folks and would recommend them highly for diesel mechanic work.

G&J has earned an excellent reputation in the area. I needed a laundry list of items looked at on my 2nd gen Cummins and they did a great job confirming and remedying some serious issues, like the lift pump delivering dangerously low PSI to the injector pump.Diagnostics are not free here, but I appreciate that Im more likely to get honest professional opinions and suggestions without the bottom line conflict of interest that drives some shady behavior in the industry.Ill be back for sure!

Had injectors pop tested here on my 5.9. They seemed knowledgeable and the pricing was beyond fair.

They did an awesome job for me! My 2015 diesel Grand Cherokee runs like a TOP & is getting well over 30mpg on the highway!! I totally recommend G & J Diesel!

I have used G&J on multiple occasions. Top notch service every time.

They do great work and have a friendly staff.

Chevy crapped the bed on my way home from Cooke city to Michigan and they had the parts I needed IN STOCK and great customer service. Thanks guys!!

Very fast service replacing my F-350 GPR and doing diagnostics on the 4WD auto system - very satisfied and will go back for any future truck issues!

They were a big help. Wouldnt go anywhere else in Billings.

WARNING! Dont take your vehicle here! My husband took his pickup in over a week ago--three times they moved the day it would be ready. Over a week later, still havent begun working on it AND charged him $176 diagonistic fee to pick it up and take it somewhere else. Bad customer relations. Called to see if they would make it right--they will not.

Fast and friendly service. professional and knowledgable, woiuld surely recommend. They were fast to repsond to my questions and needs. Phone was answered on the first call.

After taking my truck in for a no hot start problem. They quoted me 7000 in repair. Wanted to replace many items NOT even broken. Said 3 injectors, were bad, but wanted to replace all 8. Wanted to replace the HP oil pump, ECT. After 10 min research on the web, seems this is a common problem. Replace the Snap to Connect fitting, and check the ICP sensor. worse yet they left a dirty/oily rag on the floor, oil hand prints on the door leather, did not reconnect some sort of tube, and left some sort of metal ring sliding on another tube. I may not be a mechanic, but as an engineer I am good at figuring things out

They try very hard to help and advise. They listen carefully to your problems and try to solve them

Highly knowledgeable and informative diesel shop.

Great people.

I used G & J to order my air dog because I don’t have any dealers near me and they were very fast and professional about it. They specialized in fass systems but ordered me an air dog and shipped it straight to my house without trying to force me into a fass. Thanks a bunch guys!

Great service

Thanks for all the and info.

Great work on the old Dodge!!!

Place is a joke sold us $700 dollar part that would not work after I told them the tuning wouldnt work they told me they would refund it since I was broke down and needed tuning asap I called another performance place in great falls they got me back on road as soon as I got to my Destination in Washington I contacted owner to send the product back he told me I was out of luck and hung up phone

They dont call you back and dont call at lunch cause you wont get no one weird way to do business if you ask me